Default s5 running on low graphics?

Hey guys, just a quick question. Modern Combat 4, which ran on high graphics on my HTC one m7 (you can tell because of the sparks on the menu screen) is not doing so on the s5. Not to sure why. Also I've noticed that Asphalt 8 on high graphics has a bit of a lag. The S5 is awesome. Just want to know if you guys experienced this and why it could be happening. Would rooting the device help?

Thanks in advance. Cheers!!!